6.4 Limitations on ARM and AMD
We also tried to reproduce the Meltdown bug on several
ARM and AMD CPUs. However, we did not manage
to successfully leak kernel memory with the attack described
in Section 5, neither on ARM nor on AMD. The
reasons for this can be manifold. First of all, our implementation
might simply be too slow and a more optimized
version might succeed. For instance, a more shallow
out-of-order execution pipeline could tip the race
condition towards against the data leakage. Similarly,
if the processor lacks certain features, e.g., no re-order
buffer, our current implementation might not be able to
leak data. However, for both ARM and AMD, the toy
example as described in Section 3 works reliably, indicating
that out-of-order execution generally occurs and
instructions past illegal memory accesses are also performed.
